Remove Go 1.1 and Go 1.2 support

sync.Pool works mit Go 1.3 up only

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index a4d6cc5..ea95033 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,6 @@
 sudo: false
 language: go
 go:
-  - 1.1
-  - 1.2
   - 1.3
   - 1.4
   - tip